Airtel Xstream Fiber DNS not working.

[saurabhshri]

Hi, today a bunch of my devices started having internet issues. They would connect to WiFi just OK, but without internet. Local cross-device communication worked fine as well. Few devices (all my work stations) worked fine. The only difference I could think from networking perspective to fiber was that my workstations use Cloudflare's Open DNS.

I was able to test this out by manually setting static IP configuration in my devices with cloudflare DNS and it worked. For now I have set them globally in ONT settings to use Cloudflare, but I was wondering what could be the issue?

Is anybody else facing this problem?

--
Setup :

1. Airtel provided ONT : H660GM-A from DASAN Networks.
2. Primary DNS 202.56.224.132 Secondary DNS 59.144.144.45
3. DHCP settings now (two reserved IPs are for for another router which I am using as repeater, and a TV)

Screenshot-2023-04-16-at-6-49-58-PM hosted at ImgBB

Image Screenshot-2023-04-16-at-6-49-58-PM hosted on ImgBB

ibb.co

Screenshot-2023-04-16-at-6-49-42-PM hosted at ImgBB

Image Screenshot-2023-04-16-at-6-49-42-PM hosted on ImgBB

ibb.co

4. LAN1 from the ONT is used in another router with DHCP disabled to be used as another access point for different section of house.

 

[albonycal]

Looks like those DNS servers are down, maybe the process on airtel server crashed

 dig @202.56.224.132 google.com
;; communications error to 202.56.224.132#53: timed out
;; communications error to 202.56.224.132#53: timed out

 

[Sushubh]

probably a good idea to have dns configured on all your devices. i do not see any real benefit in using airtel dns considering there is no peering benefits or anything?

 

[saurabhshri]

@albonycal that seems about right. How are people not reporting this as an issue already? Is it just bad configuration on my end (like a stale configuration maybe)?

@Sushubh Unfortunately that's not a possibility, specially with all the smart devices. I ended up setting it on ONT level for all clients (see the screenshot from the post). Any reason one would not want to set it globally, but per device?

 

[Sushubh]

coz it applies even when you are on the road? and you can use something like NextDNS to get better control over what you want to block and so on.

 

[saurabhshri]

Ah, of course, that way. Yes, that makes sense -- and that's the reason my workstations were already configured to use custom DNS. Thanks for the suggestion.